perf_counter tools: Introduce stricter C code checking

Tighten up our C code requirements:

 - disallow warnings
 - disallow declarations-mixed-with-statements
 - require proper prototypes
 - require C99 (with gcc extensions)

Fix up a ton of problems these measures unearth:

 - unused functions
 - needlessly global functions
 - missing prototypes
 - code mixed with declarations

Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: John Kacur <jkacur@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <20090526222155.GJ4424@ghostprotocols.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/Documentation/perf_counter/Makefile b/Documentation/perf_counter/Makefile
index 10c13a6..efb0589 100644
--- a/Documentation/perf_counter/Makefile
+++ b/Documentation/perf_counter/Makefile
@@ -159,7 +159,7 @@
 
 # CFLAGS and LDFLAGS are for the users to override from the command line.
 
-CFLAGS = -ggdb3 -Wall
+CFLAGS = -ggdb3 -Wall -Werror -Wstrict-prototypes -Wmissing-declarations -Wmissing-prototypes -std=gnu99 -Wdeclaration-after-statement
 LDFLAGS = -lpthread -lrt -lelf
 ALL_CFLAGS = $(CFLAGS)
 ALL_LDFLAGS = $(LDFLAGS)