ARC: pt_regs update #0: remove kernel stack canary

This stack slot is going to be used in subsequent commits
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

arch/arc/include/asm/entry.h

@@ -326,10 +326,6 @@
 	/* With current tsk in r9, get it's kernel mode stack base */
 	GET_TSK_STACK_BASE  r9, r9
 
-#ifdef PT_REGS_CANARY
-	st	0xabcdabcd, [r9, 0]
-#endif
-
 	/* Save Pre Intr/Exception User SP on kernel stack */
 	st.a    sp, [r9, -12]	; Make room for orig_r0 and orig_r8
 
@@ -437,11 +433,6 @@
 	lr	r9, [erbta]
 	st.a    r9, [sp, -4]
 
-#ifdef PT_REGS_CANARY
-	mov   r9, 0xdeadbeef
-	st    r9, [sp, -4]
-#endif
-
 	/* move up by 1 word to "create" pt_regs->"stack_place_holder" */
 	sub sp, sp, 4
 .endm
@@ -540,10 +531,6 @@
 	lr	r9, [bta_l1]
 	st.a    r9, [sp, -4]
 
-#ifdef PT_REGS_CANARY
-	mov   r9, 0xdeadbee1
-	st    r9, [sp, -4]
-#endif
 	/* move up by 1 word to "create" pt_regs->"stack_place_holder" */
 	sub sp, sp, 4
 .endm
@@ -575,11 +562,6 @@
 	lr	r9, [bta_l2]
 	st.a    r9, [sp, -4]
 
-#ifdef PT_REGS_CANARY
-	mov   r9, 0xdeadbee2
-	st    r9, [sp, -4]
-#endif
-
 	/* move up by 1 word to "create" pt_regs->"stack_place_holder" */
 	sub sp, sp, 4
 .endm