ep93xx: clock: Fix UAF in ep93xx_clk_register_gate()

arch/arm/mach-ep93xx/clock.c:154:2: warning: Use of memory after it is freed [clang-analyzer-unix.Malloc]
arch/arm/mach-ep93xx/clock.c:151:2: note: Taking true branch
if (IS_ERR(clk))
^
arch/arm/mach-ep93xx/clock.c:152:3: note: Memory is released
kfree(psc);
^~~~~~~~~~
arch/arm/mach-ep93xx/clock.c:154:2: note: Use of memory after it is freed
return &psc->hw;
^ ~~~~~~~~

Fixes: 9645ccc7 ("ep93xx: clock: convert in-place to COMMON_CLK")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@gmail.com>
Cc: stable@vger.kernel.org
Link: https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org/thread/B5YCO2NJEXINCYE26Y255LCVMO55BGWW/Signed-off-by: Arnd Bergmann <arnd@arndb.de>

arch/arm/mach-ep93xx/clock.c

@@ -148,8 +148,10 @@ static struct clk_hw *ep93xx_clk_register_gate(const char *name,
 	psc->lock = &clk_lock;
 
 	clk = clk_register(NULL, &psc->hw);
-	if (IS_ERR(clk))
+	if (IS_ERR(clk)) {
 		kfree(psc);
+		return ERR_CAST(clk);
+	}
 
 	return &psc->hw;
 }