tools: proftool: Fix potential memory leaks

Dynamic memory, referenced by 'line', is allocated by calling
function 'calloc' and lost when the function terminates with code -1.

Signed-off-by: Maks Mishin <maks.mishinFZ@gmail.com>
diff --git a/tools/proftool.c b/tools/proftool.c
index af2cdb6..c7b427f 100644
--- a/tools/proftool.c
+++ b/tools/proftool.c
@@ -676,6 +676,7 @@
 		if (!tok) {
 			error("Invalid trace config data on line %d\n",
 			      linenum);
+			free(line);
 			return -1;
 		}
 		if (0 == strcmp(tok, "include-func")) {
@@ -685,6 +686,7 @@
 		} else {
 			error("Unknown command in trace config data line %d\n",
 			      linenum);
+			free(line);
 			return -1;
 		}
 
@@ -692,6 +694,7 @@
 		if (!tok) {
 			error("Missing pattern in trace config data line %d\n",
 			      linenum);
+			free(line);
 			return -1;
 		}