usb: host: ehci-dbg: convert macro to inline function

This patch converts macros into inline functions since the usage of
second is encouraged by Coding Style instead of the first.

Macros converted to functions:
 - dbg_status
 - dbg_cmd
 - dbg_port
 - speed_char

The size after changes remains the same.

Before:
text  data bss dec   hex  filename
36920 81   12  37013 9095 drivers/usb/host/ehci-hcd.o

After:
text  data bss dec   hex  filename
36920 81   12  37013 9095 drivers/usb/host/ehci-hcd.o

Signed-off-by: Geyslan G. Bem <geyslan@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>