main/postmarketos-initramfs: don't fallback looking for /boot when given uuid or path (MR 4775)

fixes #2562

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

main/postmarketos-initramfs/APKBUILD

 # Maintainer: Oliver Smith <ollieparanoid@postmarketos.org>
 # Co-Maintainer: Clayton Craft <clayton@craftyguy.net>
 pkgname=postmarketos-initramfs
-pkgver=2.5.0
+pkgver=2.5.1
 pkgrel=0
 pkgdesc="Base files for the postmarketOS initramfs / initramfs-extra"
 url="https://postmarketos.org"
@@ -88,7 +88,7 @@ sha512sums="
 ab41b45b0613f25a61114ed8c8b92bc53c60838f6e2e0ba18c76e5369b2984e6023a0661887692673aca3f647f268c468a468f6b1ac424cfee609017a89481dd  00-initramfs-base.files
 8a4adad3785af474b36a09a05f6a3b2c4b4f43aac331a53b903abfa51ea12be1e3d1d807b7a6e66a1346815f3b0044daf8cd62e21e2dc75d2db13ee265a72985  00-initramfs-extra-base.files
 b1462989633c65a102e7ae7ced9c41a00673b4c7434cd3fe16c229c39bb870d7e850b0d317487191b7d7ca32c75b2eed1561b1facf405bd4d876d32c71badcf3  init.sh
-199c997ecb7f6666cddc2552cecb86613105992f4868394bba367a2e3c0847b40d0fc9556c91eca3eebac8330595ebe80a95fba84a462a81cc183c713c48ca44  init_functions.sh
+9c7225abc312342b1aab55b9619a504bb58f51d9c09700bf5b57e03327d5792aafea1d5086701199501e76b94b22b7f112ca39be537ade773eef107d7bae113a  init_functions.sh
 ba3275a9af788c7c782322a22a0f144d5e50e3498ea6886486a29331f23ae89cd32d500a3635cfa7cab369afba92edc18aeca64ccbf0cd589061cce23d15b46c  unudhcpd.conf
 675e7d5bee39b2df7d322117f8dcaccc274d61beaf4d50ead19bbf2109446d64b1c0aa0c5b4f9846eb6c1c403418f28f6364eff4537ba41120fbfcbc484b7da7  mdev.conf
 "

main/postmarketos-initramfs/init_functions.sh

@@ -254,6 +254,10 @@ find_boot_partition() {
 			if [ -n "$path" ]; then
 				PMOS_BOOT="$path"
 				break
+			else
+				# Don't fall back to anything if the given UUID wasn't
+				# found
+				return
 			fi
 		fi
 	done
@@ -269,6 +273,10 @@ find_boot_partition() {
 				if [ -e "$path" ]; then
 					PMOS_BOOT="$path"
 					break
+				else
+					# Don't fall back to anything if the given path doesn't
+					# exist
+					return
 				fi
 			fi
 		done