drivers/misc/spear13xx_pcie_gadget.c: fix a memory leak in spear_pcie_gadget_probe error path

In the case of goto err_kzalloc, we should kfree target.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Pratyush Anand <pratyush.anand@st.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>