checkpatch.pl: fix unescaped left brace warnings

Basically, same as upstream 4e5d56bdf892e18832a6540b63ebf709966bce2a.

Unescaped left brace in string literals is deprecated since
perl v5.21.1.

Change-Id: I0e5f23bef821d2dca6ff4909ddbb06f4992718d4
Signed-off-by: Paul Fertser <fercerpav@gmail.com>
Reviewed-on: http://openocd.zylin.com/3228
Tested-by: jenkins
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>

tools/scripts/checkpatch.pl

@@ -2225,7 +2225,7 @@ sub process {
 # function brace can't be on same line, except for #defines of do while,
 # or if closed on same line
 		if (($line=~/$Type\s*$Ident\(.*\).*\s{/) and
-		    !($line=~/\#\s*define.*do\s{/) and !($line=~/}/)) {
+		    !($line=~/\#\s*define.*do\s\{/) and !($line=~/}/)) {
 			ERROR("OPEN_BRACE",
 			      "open brace '{' following function declarations go on the next line\n" . $herecurr);
 		}
@@ -2493,8 +2493,8 @@ sub process {
 ## 		}
 
 #need space before brace following if, while, etc
-		if (($line =~ /\(.*\){/ && $line !~ /\($Type\){/) ||
-		    $line =~ /do{/) {
+		if (($line =~ /\(.*\)\{/ && $line !~ /\($Type\){/) ||
+		    $line =~ /do\{/) {
 			ERROR("SPACING",
 			      "space required before the open brace '{'\n" . $herecurr);
 		}