*: make exec failure message more consistent

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

mailutils/mime.c

@@ -288,8 +288,8 @@ static int parse(const char *boundary, char **argv)
 					xsetenv("CHARSET", charset);
 					xsetenv("ENCODING", encoding);
 					xsetenv("FILENAME", filename);
-					BB_EXECVP(*argv, argv);
-					_exit(EXIT_FAILURE);
+					BB_EXECVP(argv[0], argv);
+					bb_perror_msg_and_die("can't execute '%s'", argv[0]);
 				}
 				// parent dumps to fd[1]
 				close(fd[0]);