The "progress" macro can be used only from within the .prefix section.
At the point of calling relocate(), we are running in .text16 and so
the near call to print_message() will end up calling a random function
somewhere in .text16.

Interestingly, this problem has remained unnoticed for some time.  It
is rare to build with DEBUG=libprefix.  In the few cases that it has
been used during development, the randomly selected function in
.text16 seems to have been a harmless no-op with no visible
side-effects (beyond the unnoticed failure to print the "relocate"
progress message).

Fix by removing the futile attempt to print a progress message before
calling relocate().

Reported-by: Raed Salem <raeds@mellanox.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>