Fixed an ebuild bug related to .pyw file permissions

If fpdb is installed using an ebuild for the very first time then fperms mysteriously fails marking the *.pyw files as executables. During a second
install from the ebuild fperms was working which is more mysterious. I have found notices about this behaviour of fperms but couldn't find a proper
solution. However simply replacing fperms with chmod just does the work done.

Signed-off-by: steffen123 <steffen@schaumburger.info>

packaging/gentoo/current_stable.ebuild

@@ -49,7 +49,7 @@ src_install() {
 	make_desktop_entry ${PN}
 
 	prepgamesdirs
-	fperms +x "${GAMES_DATADIR}"/${PN}/pyfpdb/*.pyw
+	chmod +x ${D}/"${GAMES_DATADIR}"/${PN}/pyfpdb/*.pyw
 }
 
 pkg_postinst() {

packaging/gentoo/current_testing.ebuild

@@ -49,7 +49,7 @@ src_install() {
 	make_desktop_entry ${PN}
 
 	prepgamesdirs
-	fperms +x "${GAMES_DATADIR}"/${PN}/pyfpdb/*.pyw
+	chmod +x ${D}/"${GAMES_DATADIR}"/${PN}/pyfpdb/*.pyw
 }
 
 pkg_postinst() {