BUG: headers with BUG/BUG_ON etc. need linux/bug.h

If a header file is making use of BUG, BUG_ON, BUILD_BUG_ON, or any
other BUG variant in a static inline (i.e. not in a #define) then
that header really should be including <linux/bug.h> and not just
expecting it to be implicitly present.

We can make this change risk-free, since if the files using these
headers didn't have exposure to linux/bug.h already, they would have
been causing compile failures/warnings.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h
index c2f1f6a..753ee8b 100644
--- a/include/linux/ptrace.h
+++ b/include/linux/ptrace.h
@@ -113,6 +113,7 @@
 #include <linux/compiler.h>		/* For unlikely.  */
 #include <linux/sched.h>		/* For struct task_struct.  */
 #include <linux/err.h>			/* for IS_ERR_VALUE */
+#include <linux/bug.h>			/* For BUG_ON.  */
 
 
 extern long arch_ptrace(struct task_struct *child, long request,