Revert of free -> reset (patchset #3 id:40001 of https://codereview.chromium.org/1811723002/ )

Reason for revert:
Suspect for Win10 failures.

Original issue's description:
> free -> reset
>
> The C++ standard library uses ".reset()" where we sometimes write ".free()".
> We also use ".reset()" quite a lot.  This standardizes on ".reset()".
>
> This is one more step towards dropping SkAutoTDelete in favor of the standard
> std::unique_ptr.
>
> BUG=skia:
> GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1811723002
>
> Committed: https://skia.googlesource.com/skia/+/0e3738db89e86035ed5d4f629bf58b817b1e5274

TBR=reed@google.com,mtklein@google.com,mtklein@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:

Review URL: https://codereview.chromium.org/1813843002
diff --git a/src/codec/SkBmpCodec.cpp b/src/codec/SkBmpCodec.cpp
index e327f79..32f1d15 100644
--- a/src/codec/SkBmpCodec.cpp
+++ b/src/codec/SkBmpCodec.cpp
@@ -392,7 +392,7 @@
             alphaType = kUnpremul_SkAlphaType;
         }
     }
-    iBuffer.reset();
+    iBuffer.free();
 
     // Additionally, 32 bit bmp-in-icos use the alpha channel.
     // FIXME (msarett): Don't all bmp-in-icos use the alpha channel?