Modify file error to match real cat

src/file.S

@@ -68,19 +68,19 @@ open_fd:
     2:
     ret
 
-# Check if the given file exists without opening fd
-# @param[in] a0: ptr to null-terminated file str.
-# @param[out] a0: result code (0-exists 1-doesn't exist).
-file_exists:
-    mv a1, a0
-    li a0, -100 # relative/absolute path
-    li a2, 0
-    li a7, 48
-    ecall
-    beqz a0, 1f
-    li a0, 1
-    ret
+# # Check if the given file exists without opening fd
+# # @param[in] a0: ptr to null-terminated file str.
+# # @param[out] a0: result code (0-exists 1-doesn't exist).
+# file_exists:
+#     mv a1, a0
+#     li a0, -100 # relative/absolute path
+#     li a2, 0
+#     li a7, 48
+#     ecall
+#     beqz a0, 1f
+#     li a0, 1
+#     ret
 
-    1:
-    li a0, 0
-    ret
+#     1:
+#     li a0, 0
+#     ret