soc: bcm: brcmstb: biuctrl: fix of_iomap leak

Smatch reports:

drivers/soc/bcm/brcmstb/biuctrl.c:291 setup_hifcpubiuctrl_regs() warn:
'cpubiuctrl_base' from of_iomap() not released on lines: 291.

This is because in setup_hifcpubiuctrl_regs(),
cpubiuctrl_base is not released when handle error, which may cause a leak.
To fix this, iounmap is added when handle error.

Fixes: 22f7a9116eba ("soc: brcmstb: Correct CPU_CREDIT_REG offset for Brahma-B53 CPUs")
Signed-off-by: Zhaoyang Li <[e-mail]>
Reviewed-by: Dan Carpenter <[e-mail]>
Reviewed-by: Dongliang Mu <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Florian Fainelli <[e-mail]>

drivers/soc/bcm/brcmstb/biuctrl.c

···
 	if (BRCM_ID(family_id) == 0x7260 && BRCM_REV(family_id) == 0)
 		cpubiuctrl_regs = b53_cpubiuctrl_no_wb_regs;
 out:
+	if (ret && cpubiuctrl_base) {
+		iounmap(cpubiuctrl_base);
+		cpubiuctrl_base = NULL;
+	}
 	return ret;
 }