Update build_style for all templates.

- There's no need to set build_style for custom-install (default).
- gnu_{configure,makefile} renamed to gnu-{configure,makefile}.

srcpkgs/e2fsprogs/template

@@ -3,7 +3,7 @@ pkgname=e2fsprogs
 version=1.41.14
 revision=2
 distfiles="$SOURCEFORGE_SITE/e2fsprogs/$pkgname-$version.tar.gz"
-build_style=gnu_configure
+build_style=gnu-configure
 configure_args="--enable-htree --enable-elf-shlibs --disable-fsck
 --enable-e2initrd-helper --disable-rpath --with-root-prefix=
 -disable-uuidd --disable-libuuid --disable-libblkid