Add stack checking for Blackfin

Simply fill out the bits in checkstack.pl for Blackfin.  I thought I already
sent this, but I don't see it in -mm anywhere ...
Signed-off-by: NMike Frysinger <vapier@gentoo.org>
Cc: Bryan Wu <bryan.wu@analog.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

scripts/checkstack.pl

@@ -78,6 +78,9 @@ my (@stack, $re, $x, $xs);
 		#     pair for larger users. -- PFM.
 		#a00048e0:       d4fc40f0        addi.l  r15,-240,r15
 		$re = qr/.*addi\.l.*r15,-(([0-9]{2}|[3-9])[0-9]{2}),r15/o;
+	} elsif ($arch =~ /^blackfin$/) {
+		#   0:   00 e8 38 01     LINK 0x4e0;
+		$re = qr/.*[[:space:]]LINK[[:space:]]*(0x$x{1,8})/o;
 	} else {
 		print("wrong or unknown architecture\n");
 		exit