Coverity fixes - 12023, 12024, and 12025

. 12023 - Ignoring number of bytes read
  basicInit (ldclt.c):
  The return value from fread was ignored and not used for copying
  the read content from buffer to mctx.attrplFileContent.
. 12024 - Resource leak
  roles_cache_create_object_from_entry (roles_cache.c):
  When an error occurred, filter_attr_value was not freed.
. 12025 - Wrong sizeof argument
  read_metadata (dblayer.c):
  prfinfo is declared as PRFileInfo64, but when initializing the
  structure with NULL, the specified size was for PRFileInfo.

Reviewed by rmeggins (Thank you, Rich!!)

ldap/servers/plugins/roles/roles_cache.c

@@ -1261,6 +1261,7 @@ static int roles_cache_create_object_from_entry(Slapi_Entry *role_entry, role_ob
 					    (char*)slapi_sdn_get_ndn(this_role->dn),
 					    ROLE_FILTER_ATTR_NAME, filter_attr_value,
 					    ROLE_FILTER_ATTR_NAME);
+					slapi_ch_free_string(&filter_attr_value);
 					slapi_ch_free((void**)&this_role);
 					return SLAPI_ROLE_ERROR_FILTER_BAD;
 				}
@@ -1270,7 +1271,7 @@ static int roles_cache_create_object_from_entry(Slapi_Entry *role_entry, role_ob
 
 			/* Turn it into a slapi filter object */
 			filter = slapi_str2filter(filter_attr_value);
-			slapi_ch_free((void**)&filter_attr_value);
+			slapi_ch_free_string(&filter_attr_value);
 
 			if ( filter == NULL ) 
 			{

ldap/servers/slapd/back-ldbm/dblayer.c

@@ -5226,7 +5226,7 @@ static int read_metadata(struct ldbminfo *li)
     /* Open the guard file and read stuff, then delete it */
     PR_snprintf(filename,sizeof(filename),"%s/guardian",priv->dblayer_home_directory);
 
-    memset(&prfinfo, '\0', sizeof(PRFileInfo));
+    memset(&prfinfo, '\0', sizeof(PRFileInfo64));
     (void)PR_GetFileInfo64(filename, &prfinfo);
 
     prfd = PR_Open(filename,PR_RDONLY,priv->dblayer_file_mode);

ldap/servers/slapd/tools/ldclt/ldclt.c

@@ -1584,20 +1584,24 @@ basicInit (void)
     /* start to read file content */
     mctx.attrplFileContent = (char *)malloc(mctx.attrplFileSize + 1);    
     i=0;
-    while ( fread(buffer, BUFFERSIZE , 1, attrF) )
+    while ( (ret = fread(buffer, BUFFERSIZE , 1, attrF)) )
     {
-      memcpy(mctx.attrplFileContent+i, buffer , BUFFERSIZE );
-      memset(buffer ,'\0', BUFFERSIZE );
-      i = i + BUFFERSIZE;
+      memcpy(mctx.attrplFileContent+i, buffer , ret);
+      memset(buffer ,'\0', BUFFERSIZE);
+      i += ret;
     } 
     /* copy remainding content into mctx.attrplFileContent */
+    /* ??? 
+     * Why you need to copy buffer twice to fill the gap?
+     * Could there any chance (mctx.attrplFileSize - 1 - i) > BUFFERSIZE ?
+     */
     if (i<mctx.attrplFileSize)
     {
       memcpy(mctx.attrplFileContent+i, buffer , (mctx.attrplFileSize - 1 - i));
       memset(buffer ,'\0', BUFFERSIZE );  /* clear the buffer */
     }
 
-    mctx.attrplFileContent[mctx.attrplFileSize]='\0'; // append the close bit
+    mctx.attrplFileContent[mctx.attrplFileSize]='\0'; /* append the close bit */
 
     if ((fclose(attrF)) == EOF )
     {