Fix typo in comment.

Change-Id: I77733d7afaf473b39523b5bec77e4e5251e76a37
diff --git a/av1/encoder/encoder.c b/av1/encoder/encoder.c
index 73e7b58..471742e 100644
--- a/av1/encoder/encoder.c
+++ b/av1/encoder/encoder.c
@@ -5408,7 +5408,7 @@
 #if CONFIG_SUPERRES_IN_RECODE
   if (superres_in_recode_allowed(cpi) && cpi->superres_mode != SUPERRES_NONE &&
       cm->superres_scale_denominator == SCALE_NUMERATOR) {
-    // Superres mode in currently enabled, but the denominator selected will
+    // Superres mode is currently enabled, but the denominator selected will
     // disable superres. So no need to continue, as we will go through another
     // recode loop for full-resolution after this anyway.
     return -1;