power: fg-alg: return -1 instead of -EINVAL on error

Align our code to the return value found in other versions of the patch
"power: qpnp-qg: Add TTF_VALID param for valid TTF/TTE reporting".

This stops the time_to_full_now attribute from returning -22 (-EINVAL)
when the battery is fully charged which VTS is not happy about.

Issue: FP3-A12#4
Issue: FP3-A11#355
Test: run vts -m VtsHalHealthV2_1TargetTest -t PerInstance/HealthHidlTest#getHealthInfo_2_1/0_default
Change-Id: Ib36d74a4cbed0c125217bd15c07de5eff2c42659
(cherry picked from commit 4f6dc7409ee10da81aa3c91aa0fffb8f9522e3c8)
diff --git a/drivers/power/supply/qcom/fg-alg.c b/drivers/power/supply/qcom/fg-alg.c
index 09c3fc4..12652e6 100644
--- a/drivers/power/supply/qcom/fg-alg.c
+++ b/drivers/power/supply/qcom/fg-alg.c
@@ -813,7 +813,7 @@
 	}
 
 	if (!valid) {
-		*val = -EINVAL;
+		*val = -1;
 		return 0;
 	}
 
@@ -824,7 +824,7 @@
 	}
 
 	if (charge_status != POWER_SUPPLY_STATUS_CHARGING) {
-		*val = -EINVAL;
+		*val = -1;
 		return 0;
 	}
 
@@ -1145,7 +1145,7 @@
 	}
 
 	if (!valid) {
-		*val = -EINVAL;
+		*val = -1;
 		return 0;
 	}
 
@@ -1156,7 +1156,7 @@
 	}
 
 	if (charge_status == POWER_SUPPLY_STATUS_CHARGING) {
-		*val = -EINVAL;
+		*val = -1;
 		return 0;
 	}