perf tools: Fix LIBELF_MMAP checking

Currently checking mmap support in libelf failed due to wrong flags.

    CHK libelf
    CHK libdw
    CHK libunwind
    CHK -DLIBELF_MMAP
/tmp/ccYJwdR0.o: In function `main':
:(.text+0x18): undefined reference to `elf_begin'
collect2: error: ld returned 1 exit status

This cannot happen since we checked the elf_begin() when checking
libelf and it succeeded.

Fix it by using a same flag with libelf checking.

Signed-off-by: Namhyung Kim <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

Author: Namhyung Kim

tools/perf/Makefile

@@ -541,7 +541,8 @@ LIB_OBJS += $(OUTPUT)util/symbol-minimal.o
 else # NO_LIBELF
 BASIC_CFLAGS += -DLIBELF_SUPPORT
 
-ifeq ($(call try-cc,$(SOURCE_ELF_MMAP),$(FLAGS_COMMON),-DLIBELF_MMAP),y)
+FLAGS_LIBELF=$(ALL_CFLAGS) $(ALL_LDFLAGS) $(EXTLIBS)
+ifeq ($(call try-cc,$(SOURCE_ELF_MMAP),$(FLAGS_LIBELF),-DLIBELF_MMAP),y)
 	BASIC_CFLAGS += -DLIBELF_MMAP
 endif