powerpc/ftrace: Fix assembly trampoline register usage

commit fd5a4298 upstream.

Just like the module loader, ftrace needs to be updated to use r12
instead of r11 with newer gcc's.
Signed-off-by: Roger Blofeld <blofeldus@yahoo.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

arch/powerpc/kernel/ftrace.c

@@ -245,9 +245,9 @@ __ftrace_make_nop(struct module *mod,
 
 	/*
 	 * On PPC32 the trampoline looks like:
-	 *  0x3d, 0x60, 0x00, 0x00  lis r11,sym@ha
-	 *  0x39, 0x6b, 0x00, 0x00  addi r11,r11,sym@l
-	 *  0x7d, 0x69, 0x03, 0xa6  mtctr r11
+	 *  0x3d, 0x80, 0x00, 0x00  lis r12,sym@ha
+	 *  0x39, 0x8c, 0x00, 0x00  addi r12,r12,sym@l
+	 *  0x7d, 0x89, 0x03, 0xa6  mtctr r12
 	 *  0x4e, 0x80, 0x04, 0x20  bctr
 	 */
 
@@ -262,9 +262,9 @@ __ftrace_make_nop(struct module *mod,
 	pr_devel(" %08x %08x ", jmp[0], jmp[1]);
 
 	/* verify that this is what we expect it to be */
-	if (((jmp[0] & 0xffff0000) != 0x3d600000) ||
-	    ((jmp[1] & 0xffff0000) != 0x396b0000) ||
-	    (jmp[2] != 0x7d6903a6) ||
+	if (((jmp[0] & 0xffff0000) != 0x3d800000) ||
+	    ((jmp[1] & 0xffff0000) != 0x398c0000) ||
+	    (jmp[2] != 0x7d8903a6) ||
 	    (jmp[3] != 0x4e800420)) {
 		printk(KERN_ERR "Not a trampoline\n");
 		return -EINVAL;