ALSA: rawmidi: Undo my 4.4.144 resolution

This reverts commit 01b6ca65 ("ALSA: rawmidi: Change resized buffers
atomically") in favor of commit 6d021f4b ("ANDROID: sound: rawmidi:
Hold lock around realloc").

This matches Qualcomm's resolution: https://source.codeaurora.org/quic/la/kernel/msm-4.4/commit/?id=facb909e66d37224f564750e8ebc693b91934ec6



Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>