mfd: stmpe: Only disable the regulators if they are enabled

In stmpe_probe(), if some regulator_enable() calls fail, probing continues
and there is only a dev_warn().

So, if stmpe_probe() is called the regulator may not be enabled. It is
cleaner to test it before calling regulator_disable() in the remove
function.

Fixes: 9c9e321455fb ("mfd: stmpe: add optional regulators")
Signed-off-by: Christophe JAILLET <[e-mail]>
Reviewed-by: Linus Walleij <[e-mail]>
Link: https://lore.kernel.org/r/8de3aaf297[e-mail]
Signed-off-by: Lee Jones <[e-mail]>

drivers/mfd/stmpe.c

···
 
 void stmpe_remove(struct stmpe *stmpe)
 {
-	if (!IS_ERR(stmpe->vio))
+	if (!IS_ERR(stmpe->vio) && regulator_is_enabled(stmpe->vio))
 		regulator_disable(stmpe->vio);
-	if (!IS_ERR(stmpe->vcc))
+	if (!IS_ERR(stmpe->vcc) && regulator_is_enabled(stmpe->vcc))
 		regulator_disable(stmpe->vcc);
 
 	__stmpe_disable(stmpe, STMPE_BLOCK_ADC);