Revert "Remove the needless, error-causing realpaths"

This reverts commit c071fc4cc4.

astronaut/astronaut

@@ -54,19 +54,19 @@ while getopts "h?s:b:i:p:r:IcCdvo:" opt; do
             exit 0
             ;;
         s)
-            dir_source="$OPTARG"
+            dir_source="$(realpath "$OPTARG")"
             ;;
         b)
-            dir_build="$OPTARG"
+            dir_build="$(realpath "$OPTARG")"
             ;;
         i)
-            dir_install="$OPTARG"
+            dir_install="$(realpath "$OPTARG")"
             ;;
         p)
-            dir_prefix="$OPTARG"
+            dir_prefix="$(realpath "$OPTARG")"
             ;;
         r)
-            dir_sysroot="$OPTARG"
+            dir_sysroot="$(realpath "$OPTARG")"
             ;;
         I)
             _nuke_dir_install=true