add CONFIG_ENABLE_MUST_CHECK

Those 1500 warnings can be a bit of a pain.  Add a config option to shut them
up.

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

include/linux/compiler.h

diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index 9b4f110..060b961 100644
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -99,6 +99,11 @@
 #define __must_check
 #endif
 
+#ifndef CONFIG_ENABLE_MUST_CHECK
+#undef __must_check
+#define __must_check
+#endif
+
 /*
  * Allow us to avoid 'defined but not used' warnings on functions and data,
  * as well as force them to be emitted to the assembly file.