gptfdisk: fix installation step

The installation step was not giving the full destination path even
though it was using -D, and it was forgetting to explicitly specify
the permissions of the file to install. This commit fixes both of
these minor issues.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

package/gptfdisk/gptfdisk.mk

@@ -22,7 +22,7 @@ endef
 
 define GPTFDISK_INSTALL_TARGET_CMDS
 	for i in $(GPTFDISK_TARGETS_y); do \
-	    $(INSTALL) -D $(@D)/$$i $(TARGET_DIR)/usr/sbin/; \
+	    $(INSTALL) -D -m 0755 $(@D)/$$i $(TARGET_DIR)/usr/sbin/$$i; \
 	done
 endef