IMP(2.1x): Retrieve actual partition when symlink

Add function to retrieve actual partition from symlink in lib/utils.sh
Using this func in all 3 audit scripts

Improved tests to test this func

Apply shellcheck recommendations
Trim trailing spaces

lib/utils.sh

@@ -258,9 +258,23 @@ is_kernel_option_enabled() {
 }
 
 #
-# Mounting point 
+# Mounting point
 #
 
+get_partition_from_symlink() {
+    local local_partition="$1"
+    if [ ! -e "$local_partition" ]; then
+        return
+    fi
+    filetype=$(stat -c %F "$local_partition")
+    if [ "$filetype" == "symbolic link" ]; then
+        actual_partition=$(readlink "$local_partition" )
+        warn "$local_partition actually is $actual_partition"
+        local_partition="$actual_partition"
+    fi
+    PARTITION="$local_partition"
+}
+
 # Verify $1 is a partition declared in fstab
 is_a_partition() {