Filter bootloader supplied kernel cmdline options

Various bootloader add kernel commandline options dynamically, filter
these out when grabbing boot options from /proc/cmdline. Specifically
grub adds BOOT_IMAGE and systemd-boot adds initrd.

Closes: #560
Approved by: cgwalters

tests/test-admin-deploy-karg.sh

@@ -46,6 +46,8 @@ ${CMD_PREFIX} ostree admin deploy --karg-proc-cmdline --os=testos testos:testos/
 for arg in $(cat /proc/cmdline); do
     case "$arg" in
 	ostree=*) # Skip ostree arg that gets stripped out
+	  ;;
+	initrd=*|BOOT_IMAGE=*) # Skip options set by bootloader that gets filtered out
 	   ;;
 	*) assert_file_has_content sysroot/boot/loader/entries/ostree-testos-0.conf "options.*$arg"
 	   ;;

tests/test-admin-instutil-set-kargs.sh

@@ -58,6 +58,8 @@ for arg in $(cat /proc/cmdline); do
     case "$arg" in
 	ostree=*) # Skip ostree arg that gets stripped out
 	   ;;
+	initrd=*|BOOT_IMAGE=*) # Skip options set by bootloader that gets filtered out
+	   ;;
 	*) assert_file_has_content sysroot/boot/loader/entries/ostree-testos-0.conf "options.*$arg"
 	   ;;
     esac