When the is_s390_dump() function is called to determine whether

a file is an s390 dumpfile, it currently presumes that the fopen()
call always works, and then tries to read it with using a NULL file
pointer.  Change it to verify that the fopen() was successful, and
if not, print an error message as is done with the other dumpfile
type verifier functions.
(ramin.blackhat@gmail.com)

s390_dump.c

@@ -30,6 +30,10 @@ is_s390_dump(char *file)
 	int rc;
 
 	fh = fopen(file,"r");
+	if (fh == NULL) {
+		error(INFO, "is_s390_dump: cannot open %s: %s\n", file);
+		return FALSE;
+	}
 	items = fread(&magic, sizeof(magic), 1,fh);
 	if(magic == 0xa8190173618f23fdLL)
 		rc = TRUE;