Blackfin arch: ensure that speculative loads of bad pointers don't cause us to do bad things.

Fix/change formatting of a few more things.

Signed-off-by: Robin Getz <robin.getz@analog.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>

diff --git a/arch/blackfin/mach-common/entry.S b/arch/blackfin/mach-common/entry.S
index e3ad580..1b13fa47 100644
--- a/arch/blackfin/mach-common/entry.S
+++ b/arch/blackfin/mach-common/entry.S
@@ -917,7 +917,7 @@
 	.long _ex_soft_bp       /* 0x01 - User Defined - Software breakpoint */
 	.long _ex_replaceable   /* 0x02 - User Defined */
 	.long _ex_trap_c        /* 0x03 - User Defined - userspace stack overflow */
-	.long _ex_replaceable   /* 0x04 - User Defined */
+	.long _ex_trap_c        /* 0x04 - User Defined - dump trace buffer */
 	.long _ex_replaceable   /* 0x05 - User Defined */
 	.long _ex_replaceable   /* 0x06 - User Defined */
 	.long _ex_replaceable   /* 0x07 - User Defined */