dasdinfo: Fix memory leak in dinfo_get_uid_from_devnode()

The function dinfo_get_uid_from_devnode() allocates memory for
readbuf but fails to free it in two code paths:
1. When the device name is truncated (error path)
2. At the successful function exit

Add the missing free(readbuf) calls to prevent memory leaks in
both paths.

Reviewed-by: Jan Höppner <hoeppner@linux.ibm.com>
Signed-off-by: Volkan Unal <vunal@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>

dasdinfo/dasdinfo.c

@@ -495,6 +495,7 @@ static int dinfo_get_uid_from_devnode(char **uidfile, char *devnode)
 				fprintf(stderr,
 					"Error: Device name was truncated\n");
 				free(path);
+				free(readbuf);
 				return -1;
 			}
 
@@ -504,6 +505,7 @@ static int dinfo_get_uid_from_devnode(char **uidfile, char *devnode)
 
 	closedir(directory);
 	free(path);
+	free(readbuf);
 	return 0;
 }