clk: vc5: fix use of memory after it has been kfree'd

clk: vc5: fix use of memory after it has been kfree'd

There are a several places where printing an error message of
init.name occurs after init.name has been kfree'd. Also the failure
message is duplicated each time in the code. Fix this by adding
a registration error failure path for these cases, moving the
duplicated error messages to one common point and kfree'ing init.name
only after it has been used.

Changes also shrink the object code size by 171 bytes (x86-64, gcc 9.3):

Before:
   text	   data	    bss	    dec	    hex	filename
  21057	   3960	     64	  25081	   61f9	drivers/clk/clk-versaclock5.o

After:
   text	   data	    bss	    dec	    hex	filename
  20886	   3960	     64	  24910	   614e	drivers/clk/clk-versaclock5.o

Addresses-Coverity: ("Use after free")
Fixes: d2631a04bdff ("clk: vc5: Allow Versaclock driver to support multiple instances")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Link: https://lore.kernel.org/r/20200625132736.88832-1-colin.king@canonical.com
Reviewed-by: Luca Ceresoli <luca@lucaceresoli.net>
[sboyd@kernel.org: Drop stray newline]
Signed-off-by: Stephen Boyd <sboyd@kernel.org>