Remove exit calls from print_supported_chips

Propagate the error code using return values instead, but let cli_classic.c
still decide the ultimate return value of the process.
Also, remove setting the ret value again after print_supported_wiki() - 
success is the default.

Corresponding to flashrom svn r1614.

Signed-off-by: Niklas Söderlund <niso@kth.se>
Acked-by: Stefan Tauner <stefan.tauner@alumni.tuwien.ac.at>
diff --git a/cli_classic.c b/cli_classic.c
index 4ae375c..ccf75e9 100644
--- a/cli_classic.c
+++ b/cli_classic.c
@@ -357,14 +357,13 @@
 #if CONFIG_PRINT_WIKI == 1
 	if (list_supported_wiki) {
 		print_supported_wiki();
-		ret = 0;
 		goto out;
 	}
 #endif
 
 	if (list_supported) {
-		print_supported();
-		ret = 0;
+		if (print_supported())
+			ret = 1;
 		goto out;
 	}