ARM: 5985/2: ARM: Fix Samsung build after "ARM: Eliminate decompressor -Dstatic= PIC hack"

Commit 5de813b6 (ARM: Eliminate decompressor -Dstatic= PIC hack) among
other things changed the declared type of the error() function to an
extern, conflicting with the forward declartion in the Samsung
plat/uncompress.h which appears to have been relying on the static
being defined away, causing build failures since error() ends up with
a GOT relocation but the linker script discards all GOT relocated
data and functions:

arch/arm/boot/compressed/decompress.o: In function `gunzip':
/home/broonie/git/linux-2.6/arch/arm/boot/compressed/../../../../lib/decompress_
+inflate.c:68: undefined reference to `error'

and so on. Fix this by moving the declaration into uncompress/misc.c
where it is shared with the rest of the code, correcting the definition
as we go.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>