powerpc: Rename asm offset TRAP to _TRAP for 32-bit

... for consistency with 64-bit.

Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/kernel/head_4xx.S b/arch/powerpc/kernel/head_4xx.S
index 10c261c..2590e97 100644
--- a/arch/powerpc/kernel/head_4xx.S
+++ b/arch/powerpc/kernel/head_4xx.S
@@ -214,7 +214,7 @@
 
 #define EXC_XFER_TEMPLATE(hdlr, trap, msr, copyee, tfer, ret)	\
 	li	r10,trap;					\
-	stw	r10,TRAP(r11);					\
+	stw	r10,_TRAP(r11);					\
 	lis	r10,msr@h;					\
 	ori	r10,r10,msr@l;					\
 	copyee(r10, r9);					\