main/postmarketos-mkinitfs: only run if deviceinfo exists (MR 4263)

In some situations, like when building a device package with pmb,
deviceinfo may not exist in the rootfs. mkinitfs 2.2's behavior changed
slightly to fail if it can't find a deviceinfo, and this avoids calling
it in those cases.

[ci:skip-build]: Already built successfully in CI

main/postmarketos-mkinitfs/APKBUILD

@@ -2,7 +2,7 @@
 # Co-Maintainer: Clayton Craft <clayton@craftyguy.net>
 pkgname=postmarketos-mkinitfs
 pkgver=2.2
-pkgrel=0
+pkgrel=1
 pkgdesc="Tool to generate initramfs images for postmarketOS"
 url="https://postmarketos.org"
 depends="

main/postmarketos-mkinitfs/postmarketos-mkinitfs.trigger

 #!/bin/sh -e
 
-/usr/sbin/mkinitfs
+# only invoke mkinitfs if the deviceinfo exists in the rootfs
+{ [ -f /etc/deviceinfo ] || [ -f /usr/share/deviceinfo/deviceinfo ]; } && /usr/sbin/mkinitfs
 exit 0