prereq-build: g++ formatting and consistency fixes

Remove \n that mangles output, and fix inconsistent version name check.

Example before:

Build dependency: Please install the GNU C++ Compiler (g++) 6 or later
Build dependency: \nPlease reinstall the GNU C++ Compiler (4.8 or later) - it appears to be broken
Build dependency: Please install ncurses. (Missing libncurses.so or ncurses.h)

Signed-off-by: Karl Palsson <[email protected]>

include/prereq-build.mk

@@ -31,7 +31,7 @@ $(eval $(call SetupHostCommand,gcc, \
 	gcc --version | grep -E 'Apple.(LLVM|clang)' ))
 
 $(eval $(call TestHostCommand,working-gcc, \
-	\nPlease reinstall the GNU C Compiler (6 or later) - \
+	Please reinstall the GNU C Compiler (6 or later) - \
 	it appears to be broken, \
 	echo 'int main(int argc, char **argv) { return 0; }' | \
 		gcc -x c -o $(TMP_DIR)/a.out -))
@@ -43,7 +43,7 @@ $(eval $(call SetupHostCommand,g++, \
 	g++ --version | grep -E 'Apple.(LLVM|clang)' ))
 
 $(eval $(call TestHostCommand,working-g++, \
-	\nPlease reinstall the GNU C++ Compiler (4.8 or later) - \
+	Please reinstall the GNU C++ Compiler (6 or later) - \
 	it appears to be broken, \
 	echo 'int main(int argc, char **argv) { return 0; }' | \
 		g++ -x c++ -o $(TMP_DIR)/a.out - -lstdc++ && \