aom_encoder.h: fix rc_overshoot_pct range

the range checked has been [0, 100] for the life of AV1.

+ fix a couple other typos

Bug: aomedia:3140
Change-Id: Ia331b19d77cadb60229e8648fb10b46c6244d618
(cherry picked from commit 66d00179893b6efb22b99c35fb5f052d9e763018)

aom/aom_encoder.h

diff --git a/aom/aom_encoder.h b/aom/aom_encoder.h
index b2926e1..a0efd51 100644
--- a/aom/aom_encoder.h
+++ b/aom/aom_encoder.h
@@ -648,7 +648,7 @@
   /*!\brief Rate control adaptation undershoot control
    *
    * This value, controls the tolerance of the VBR algorithm to undershoot
-   * and is used as a trigger threshold for more agressive adaptation of Q.
+   * and is used as a trigger threshold for more aggressive adaptation of Q.
    *
    * Valid values in the range 0-100.
    */
@@ -657,9 +657,9 @@
   /*!\brief Rate control adaptation overshoot control
    *
    * This value, controls the tolerance of the VBR algorithm to overshoot
-   * and is used as a trigger threshold for more agressive adaptation of Q.
+   * and is used as a trigger threshold for more aggressive adaptation of Q.
    *
-   * Valid values in the range 0-1000.
+   * Valid values in the range 0-100.
    */
   unsigned int rc_overshoot_pct;