font.eclass: Remove racy pkg_postinst code

Noticed on ChromeOS when installing a large number of font packages in
parallel:

/usr/share/fonts/noto/NotoSerifThai-Regular.ttf#new' from 0004 (------r--) to 2440 (r--r-S---)
* ERROR: media-fonts/ipaex-004.01-r1::chromiumos failed (postinst phase):
*   failed to fix font files perms

The "#new" filename is the hint. Portage uses "#new" suffixes when
copying files to the system, and then renames them to their final
filenames.

This code was executing while another font was in the process of being
copied to the system. Font packages should just ensure that they install
files with correct permissions to begin with, and all except
media-fonts/x11fonts-jmk already use 0644 permissions.
media-fonts/x11fonts-jmk used 0444 (which was probably fine) until the
previous commit which changes its installed files to 0644.

Bug: https://bugs.gentoo.org/187774
Signed-off-by: Matt Turner <[email protected]>

eclass/font.eclass

@@ -186,12 +186,6 @@ font_src_install() {
 # @DESCRIPTION:
 # Updates fontcache if !prefix and media-libs/fontconfig installed
 _update_fontcache() {
-	if [[ -d "${EROOT}"/usr/share/fonts ]] ; then
-		# unreadable font files = fontconfig segfaults
-		find "${EROOT}"/usr/share/fonts/ -type f '!' -perm 0644 \
-			-exec chmod -v 0644 2>/dev/null {} + || die "failed to fix font files perms"
-	fi
-
 	if [[ -z ${ROOT} ]] ; then
 		if has_version media-libs/fontconfig ; then
 			ebegin "Updating global fontcache"