AVFrame: factor out freeing the side data

Signed-off-by: Anton Khirnov <anton@khirnov.net>
dcadec: replace ldexpf with a multiplication by a constant

Signed-off-by: Anton Khirnov <anton@khirnov.net>
Merge commit '44671b57866aab8dd36715ff010e985e25baaf19'

* commit '44671b57866aab8dd36715ff010e985e25baaf19':
  AVFrame: factor out freeing the side data

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit 'f2ce63246f5c934429f9cb857a794e07624d7912'

* commit 'f2ce63246f5c934429f9cb857a794e07624d7912':
  dcadec: replace ldexpf with a multiplication by a constant

Conflicts:
	libavcodec/dcadec.c

See: 6da06ef6bbc01b713f67ffb94e7697eb2393ebe4
See: 9ccb5455ca8c63eb330abd3c2ed6a9b0ae3b755e
See: 6b88f22e895314164eef00ccbdbf11ad97a7c56f
Merged-by: Michael Niedermayer <michaelni@gmx.at>
avcodec/dcadec: remove unsignedness from constant

POSIX gurantees >=32bit so it all fits in signed int
Also >=32bit ints are assumed througout the codebase

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>