chsh: Replace STRFCPY() by STRLCPY()

The variables are only being read as strings (char *), so data after the
'\0' can't be leaked.

Cc: Christian Göttsche <cgzones@googlemail.com>
Cc: Serge Hallyn <serge@hallyn.com>
Cc: Iker Pedrosa <ipedrosa@redhat.com>
Signed-off-by: Alejandro Colomar <alx@kernel.org>

src/chsh.c

@@ -31,6 +31,7 @@
 /*@-exitarg@*/
 #include "exitcodes.h"
 #include "shadowlog.h"
+#include "strlcpy.h"
 
 #ifndef SHELLS_FILE
 #define SHELLS_FILE "/etc/shells"
@@ -257,7 +258,7 @@ static void process_flags (int argc, char **argv)
 			break;
 		case 's':
 			sflg = true;
-			STRFCPY (loginsh, optarg);
+			STRLCPY(loginsh, optarg);
 			break;
 		default:
 			usage (E_USAGE);
@@ -552,7 +553,7 @@ int main (int argc, char **argv)
 	 * file, or use the value from the command line.
 	 */
 	if (!sflg) {
-		STRFCPY (loginsh, pw->pw_shell);
+		STRLCPY(loginsh, pw->pw_shell);
 	}
 
 	/*