Dont use -fPIC for cygwin builds

[XVilka]

this:

make[3]: Entering directory '/cygdrive/d/Work/radare/radare2/shlr/sdb/src'
gcc -c  -g -fPIC -o cdb.o cdb.c
cdb.c:1:0: warning: -fPIC ignored for target (all code is position independent)
 /* Public domain - author D. J. Bernstein, modified by pancake - 2014 */
 ^
gcc -c  -g -fPIC -o buffer.o buffer.c
buffer.c:1:0: warning: -fPIC ignored for target (all code is position independent)
 /* Public Domain */
 ^
gcc -c  -g -fPIC -o cdb_make.o cdb_make.c
cdb_make.c:1:0: warning: -fPIC ignored for target (all code is position independent)
 /* Public domain. */
 ^
gcc -c  -g -fPIC -o ls.o ls.c
ls.c:1:0: warning: -fPIC ignored for target (all code is position independent)
 /* sdb - LGPLv3 - Copyright 2007-2014 - pancake */
 ^

[XVilka]

Irrelevant now.