kernel: fatal: fix indentation in z_fatal_error

Fix indentation error in z_fatal_error().

Signed-off-by: Ioannis Glaropoulos <Ioannis.Glaropoulos@nordicsemi.no>
diff --git a/kernel/fatal.c b/kernel/fatal.c
index 419e5a7..f3a149c 100644
--- a/kernel/fatal.c
+++ b/kernel/fatal.c
@@ -152,26 +152,26 @@
 	} else {
 		/* Test mode */
 #if defined(CONFIG_ARCH_HAS_NESTED_EXCEPTION_DETECTION)
-			if ((esf != NULL) && arch_is_in_nested_exception(esf)) {
-				/* Abort the thread only on STACK Sentinel check fail. */
+		if ((esf != NULL) && arch_is_in_nested_exception(esf)) {
+			/* Abort the thread only on STACK Sentinel check fail. */
 #if defined(CONFIG_STACK_SENTINEL)
-				if (reason != K_ERR_STACK_CHK_FAIL) {
-					arch_irq_unlock(key);
-					return;
-				}
-#else
+			if (reason != K_ERR_STACK_CHK_FAIL) {
 				arch_irq_unlock(key);
 				return;
-#endif /* CONFIG_STACK_SENTINEL */
-			} else {
-				/* Abort the thread only if the fault is not due to
-				 * a spurious ISR handler triggered.
-				 */
-				if (reason == K_ERR_SPURIOUS_IRQ) {
-					arch_irq_unlock(key);
-					return;
-				}
 			}
+#else
+			arch_irq_unlock(key);
+			return;
+#endif /* CONFIG_STACK_SENTINEL */
+		} else {
+			/* Abort the thread only if the fault is not due to
+			 * a spurious ISR handler triggered.
+			 */
+			if (reason == K_ERR_SPURIOUS_IRQ) {
+				arch_irq_unlock(key);
+				return;
+			}
+		}
 #endif /*CONFIG_ARCH_HAS_NESTED_EXCEPTION_DETECTION */
 	}