Fix misspelling "Invaid" to "Invalid"

src/obu.c

diff --git a/src/obu.c b/src/obu.c
index 23539a6..497d7bb 100644
--- a/src/obu.c
+++ b/src/obu.c
@@ -442,7 +442,7 @@
             if (csp_present_flag) {
                 chromaSamplePosition = avifBitsRead(bits, 3);
                 if (chromaSamplePosition > 5) {
-                    // Invaid chroma_sample_position.
+                    // Invalid chroma_sample_position.
                     return AVIF_FALSE;
                 }
             }