[U-Boot] efi_loader: Fix warning in efi_load_image()

[Alexander Graf]

> As observed with clang:
> lib/efi_loader/efi_boottime.c:1624:7: warning: variable 'info'
>       is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
>                 if (ret != EFI_SUCCESS)
>                     ^~~~~~~~~~~~~~~~~~
> lib/efi_loader/efi_boottime.c:1653:7: note: uninitialized use
>       occurs here
>         free(info);
>              ^~~~
> lib/efi_loader/efi_boottime.c:1624:3: note: remove the 'if' if
>       its condition is always false
>                 if (ret != EFI_SUCCESS)
>                 ^~~~~~~~~~~~~~~~~~~~~~~
> lib/efi_loader/efi_boottime.c:1602:31: note: initialize the
>       variable 'info' to silence this warning
>         struct efi_loaded_image *info;
>                                      ^
>                                       = NULL
> 
> Rather than change how we unwind the function it makes the most sense to
> initialize info to NULL so that we can continue to pass it to free().
> 
> Fixes: c982874e930d ("efi_loader: refactor efi_setup_loaded_image()")
> Cc: Heinrich Schuchardt <xypron.glpk at gmx.de>
> Cc: Alexander Graf <agraf at suse.de>
> Signed-off-by: Tom Rini <trini at konsulko.com>
> Reviewed-by: Heinrich Schuchardt <xypron.glpk at gmx.de>

Thanks, applied to efi-2018.11

Alex