staging: rtl8192u: Delete duplicate function declarations and extern keyword

staging: rtl8192u: Delete duplicate function declarations and extern keyword

Delete the duplicate function declarations in r8192U_dm.c.

These function declarations are defined in r8192U_dm.h.

Also, delete the 'extern' keyword of these function definitions.

Fix the following sparse warnings:

  CHECK   drivers/staging/rtl8192u/r8192U_dm.c
drivers/staging/rtl8192u/r8192U_dm.c:159:1: warning: function 'init_hal_dm' with external linkage has definition
drivers/staging/rtl8192u/r8192U_dm.c:179:13: warning: function 'deinit_hal_dm' with external linkage has definition
drivers/staging/rtl8192u/r8192U_dm.c:245:17: warning: function 'hal_dm_watchdog' with external linkage has definition
drivers/staging/rtl8192u/r8192U_dm.c:278:13: warning: function 'init_rate_adaptive' with external linkage has definition
drivers/staging/rtl8192u/r8192U_dm.c:878:17: warning: function 'dm_txpower_trackingcallback' with external linkage has definition
drivers/staging/rtl8192u/r8192U_dm.c:1609:13: warning: function 'dm_cck_txpower_adjust' with external linkage has definition
drivers/staging/rtl8192u/r8192U_dm.c:1776:13: warning: function 'dm_change_dynamic_initgain_thresh' with external linkage has definition
drivers/staging/rtl8192u/r8192U_dm.c:2543:13: warning: function 'dm_init_edca_turbo' with external linkage has definition
drivers/staging/rtl8192u/r8192U_dm.c:2782:17: warning: function 'dm_rf_pathcheck_workitemcallback' with external linkage has definition
drivers/staging/rtl8192u/r8192U_dm.c:3142:13: warning: function 'dm_fsync_timer_callback' with external linkage has definition
drivers/staging/rtl8192u/r8192U_dm.c:3481:13: warning: function 'dm_shadow_init' with external linkage has definition

Signed-off-by: Ana Rey <anarey@gmail.com>
Acked-by: Luis R. Rodriguez <mcgrof@do-not-panic.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>