perf tools: Clean up warnings list in the Makefile

Make it easier to turn warnings on/off by using a separate
line for each warning added.

Some of the warnings have too much of a nuisance factor and
we might want to turn them off in the future.

Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/tools/perf/Makefile b/tools/perf/Makefile
index c481a51..9f8d207 100644
--- a/tools/perf/Makefile
+++ b/tools/perf/Makefile
@@ -169,7 +169,30 @@
 #
 # Include saner warnings here, which can catch bugs:
 #
-EXTRA_WARNINGS = -Wcast-align -Wformat -Wformat-security -Wformat-y2k -Wshadow -Winit-self -Wpacked -Wredundant-decls -Wstack-protector -Wstrict-aliasing=3 -Wswitch-default -Wswitch-enum -Wno-system-headers -Wundef -Wvolatile-register-var -Wwrite-strings -Wbad-function-cast -Wmissing-declarations -Wmissing-prototypes -Wnested-externs -Wold-style-definition -Wstrict-prototypes -Wdeclaration-after-statement
+
+EXTRA_WARNINGS := -Wcast-align
+EXTRA_WARNINGS := $(EXTRA_WARNINGS) -Wformat
+EXTRA_WARNINGS := $(EXTRA_WARNINGS) -Wformat-security
+EXTRA_WARNINGS := $(EXTRA_WARNINGS) -Wformat-y2k
+EXTRA_WARNINGS := $(EXTRA_WARNINGS) -Wshadow
+EXTRA_WARNINGS := $(EXTRA_WARNINGS) -Winit-self
+EXTRA_WARNINGS := $(EXTRA_WARNINGS) -Wpacked
+EXTRA_WARNINGS := $(EXTRA_WARNINGS) -Wredundant-decls
+EXTRA_WARNINGS := $(EXTRA_WARNINGS) -Wstack-protector
+EXTRA_WARNINGS := $(EXTRA_WARNINGS) -Wstrict-aliasing=3
+EXTRA_WARNINGS := $(EXTRA_WARNINGS) -Wswitch-default
+EXTRA_WARNINGS := $(EXTRA_WARNINGS) -Wswitch-enum
+EXTRA_WARNINGS := $(EXTRA_WARNINGS) -Wno-system-headers
+EXTRA_WARNINGS := $(EXTRA_WARNINGS) -Wundef
+EXTRA_WARNINGS := $(EXTRA_WARNINGS) -Wvolatile-register-var
+EXTRA_WARNINGS := $(EXTRA_WARNINGS) -Wwrite-strings
+EXTRA_WARNINGS := $(EXTRA_WARNINGS) -Wbad-function-cast
+EXTRA_WARNINGS := $(EXTRA_WARNINGS) -Wmissing-declarations
+EXTRA_WARNINGS := $(EXTRA_WARNINGS) -Wmissing-prototypes
+EXTRA_WARNINGS := $(EXTRA_WARNINGS) -Wnested-externs
+EXTRA_WARNINGS := $(EXTRA_WARNINGS) -Wold-style-definition
+EXTRA_WARNINGS := $(EXTRA_WARNINGS) -Wstrict-prototypes
+EXTRA_WARNINGS := $(EXTRA_WARNINGS) -Wdeclaration-after-statement
 
 CFLAGS = $(M64) -ggdb3 -Wall -Wextra -std=gnu99 -Werror -O6 -fstack-protector-all -D_FORTIFY_SOURCE=2 $(EXTRA_WARNINGS)
 LDFLAGS = -lpthread -lrt -lelf -lm