obexd: Remove magic number indicating size of buffer
obexd: Remove magic number indicating size of buffer

This patch removes "magic number" indicating buffer's size
in "vcard_printf_number" function and replace it by value defined under
LEN_MAX. Now it would be consistent with the rest of code, since all
functions from vcard_prinf_* family use LEN_MAX to indicate size
of buffer which may store some vCard's field content.

ComputeCycles/bluez,pkarasev3/bluez,ComputeCycles/bluez,silent-snowman/bluez,silent-snowman/bluez,mapfau/bluez,pstglia/external-bluetooth-bluez,silent-snowman/bluez,ComputeCycles/bluez,pkarasev3/bluez,pstglia/external-bluetooth-bluez,silent-snowman/bluez,pstglia/external-bluetooth-bluez,pkarasev3/bluez,mapfau/bluez,ComputeCycles/bluez,mapfau/bluez,pkarasev3/bluez,pstglia/external-bluetooth-bluez,mapfau/bluez