installerfw-sh-functions: fix installerfw_mnt_prefix

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>

diff --git a/installerfw-sh-functions b/installerfw-sh-functions
index 4f6374e..d865023 100644 (file)
--- a/installerfw-sh-functions
+++ b/installerfw-sh-functions
@@ -42,9 +42,7 @@ installerfw_verify_defined()
 # tripple "/" in the resulting path.
 installerfw_mnt_prefix()
 {
-       installerfw_verify_defined "INSTALLERFW_MOUNT_PREFIX"
-
-       local path="$INSTALLERFW_MOUNT_PREFIX/$1"
+       local path="${INSTALLERFW_MOUNT_PREFIX:-}/$1"
 
        printf "%s" "$path" | LC_ALL=C sed -e 's/\/\+/\//g'
 }