alpha: teach the compiler that BUG doesn't return

Fix things like this:

security/selinux/netnode.c: In function 'sel_netnode_find':
security/selinux/netnode.c:126: warning: 'idx' may be used uninitialized in this function
security/selinux/netnode.c: In function 'sel_netnode_sid':
security/selinux/netnode.c:225: warning: 'ret' may be used uninitialized in this function
security/selinux/netnode.c:168: warning: 'idx' may be used uninitialized in this function

due to code correctly not expecting BUG() to return.

For some reason this reduces the object code size for that particular file.

Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Richard Henderson <rth@twiddle.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

include/asm-alpha/bug.h

 #ifndef _ALPHA_BUG_H
 #define _ALPHA_BUG_H
 
+#include <linux/linkage.h>
+
 #ifdef CONFIG_BUG
 #include <asm/pal.h>
 
 /* ??? Would be nice to use .gprel32 here, but we can't be sure that the
    function loaded the GP, so this could fail in modules.  */
-#define BUG() \
-  __asm__ __volatile__("call_pal %0  # bugchk\n\t"".long %1\n\t.8byte %2" \
-		       : : "i" (PAL_bugchk), "i"(__LINE__), "i"(__FILE__))
+static inline void ATTRIB_NORET __BUG(const char *file, int line)
+{
+	__asm__ __volatile__(
+		"call_pal %0  # bugchk\n\t"
+		".long %1\n\t.8byte %2"
+		       : : "i" (PAL_bugchk), "i"(line), "i"(file));
+	for ( ; ; )
+		;
+}
+
+#define BUG() __BUG(__FILE__, __LINE__)
 
 #define HAVE_ARCH_BUG
 #endif