liblzma: Fix HAVE_INLINE and HAVE___INLINE checks

The checks fail even on compilers that support the keywords because
the linkage is broken:

    src.c:...: undefined reference to 'test'

At the actual use sites we use `static inline` instead of just `inline`,
so perform the check this way too to fix the linkage.

Utilities/cmliblzma/CMakeLists.txt

@@ -15,11 +15,11 @@ CHECK_C_SOURCE_COMPILES(
   HAVE___RESTRICT)
 
 CHECK_C_SOURCE_COMPILES(
-  "inline int test (void) {return 0;}\nint main (void) {return test();}"
+  "static inline int test (void) {return 0;}\nint main (void) {return test();}"
   HAVE_INLINE)
 
 CHECK_C_SOURCE_COMPILES (
-  "__inline int test (void) {return 0;}\nint main (void) {return test();}"
+  "static __inline int test (void) {return 0;}\nint main (void) {return test();}"
   HAVE___INLINE)
 
 CHECK_INCLUDE_FILE(byteswap.h HAVE_BYTESWAP_H)