fix variable type in qemu-io.c The variable len can get a negative return value from cvtnum, which we check for, but which is impossible with the current unsigned variable type. Currently the if(len < 0) check is pointless. This patch fixes that. Signed-off-by: Joel Schopp <jschopp@austin.ibm.com> Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>