Improve readability of script.

src/tools/pgindent/pgindent

@@ -51,7 +51,7 @@ do
 			    line1 !~ "^struct" &&
 			    line1 !~ "^enum" &&
 			    line1 !~ "^typedef" &&
-			    line1 !~ "extern[ 	][ 	]*\"C\"" &&
+			    line1 !~ "^extern[ 	][ 	]*\"C\"" &&
 			    line1 !~ "=" &&
 			    line1 ~ ")")
 				print "int	pgindent_func_no_var_fix;";
@@ -1477,7 +1477,7 @@ do
 	detab -t8 -qc |
 	entab -t4 -qc |
 # add space after comments that start on tab stops
-	sed 's:\([^ 	]\)\(/\*.*\*/\)$:\1	\2:' |
+	sed 's;\([^ 	]\)\(/\*.*\*/\)$;\1	\2;' |
 # move trailing * in function return type
 	sed 's;^\([A-Za-z_][^ 	]*\)[ 	][ 	]*\*$;\1 *;' |
 # remove un-needed braces around single statements