avcodec/exr: spelling

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit d80f8f36513ebff05c537adbe756e36036f80074)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavcodec/exr.c

@@ -174,7 +174,7 @@ typedef struct EXRContext {
     int is_luma;/* 1 if there is an Y plane */
 
 #define M(chr) (1<<chr - 'A')
-    int has_channel; ///< combinatin of flags representing the channel codes A-Z
+    int has_channel; ///< combination of flags representing the channel codes A-Z
 
     GetByteContext gb;
     const uint8_t *buf;