Call basename() and dirname() in the POSIXly correct way.

Pull copies of the input string, as these functions are allowed to
modify them. Free the copies after creating the new pathname string.

usr.sbin/uathload/uathload.c

@@ -50,6 +50,7 @@
 #include <libgen.h>
 #include <paths.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
 #include <strings.h>
 #include <unistd.h>
@@ -84,19 +85,30 @@ extern	uint8_t _binary_ar5523_bin_end;
 static int
 getdevname(const char *devname, char *msgdev, char *datadev)
 {
-	char *bn, *dn;
+	char *bn, *bnbuf, *dn, *dnbuf;
 
-	dn = dirname(devname);
-	if (dn == NULL)
+	dnbuf = strdup(devname);
+	if (dnbuf == NULL)
 		return (-1);
-	bn = basename(devname);
-	if (bn == NULL || strncmp(bn, "ugen", 4))
+	dn = dirname(dnbuf);
+	bnbuf = strdup(devname);
+	if (bnbuf == NULL) {
+		free(dnbuf);
 		return (-1);
+	}
+	bn = basename(bnbuf);
+	if (strncmp(bn, "ugen", 4) != 0) {
+		free(dnbuf);
+		free(bnbuf);
+		return (-1);
+	}
 	bn += 4;
 
 	/* NB: pipes are hardcoded */
 	snprintf(msgdev, 256, "%s/usb/%s.1", dn, bn);
 	snprintf(datadev, 256, "%s/usb/%s.2", dn, bn);
+	free(dnbuf);
+	free(bnbuf);
 	return (0);
 }