[PATCH v2] lib: utils/serial: Fix semihosting compile error using LLVM

[Anup Patel]

We fix the following semihosting compile error observed using LLVM:
lib/utils/serial/semihosting.c:158:12: error: result of comparison of constant -1 with expression of type 'char' is always true [-Werror,-Wtautological-constant-out-of-range-compare]
                ret = ch > -1 ? ch : -1;
                      ~~ ^ ~~

Fixes: 7f09fba86e43 ("lib: utils/serial: add semihosting support")
Signed-off-by: Anup Patel <apatel at ventanamicro.com>
---
 lib/utils/serial/semihosting.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/utils/serial/semihosting.c b/lib/utils/serial/semihosting.c
index 5012fa1..86fa296 100644
--- a/lib/utils/serial/semihosting.c
+++ b/lib/utils/serial/semihosting.c
@@ -154,8 +154,8 @@ static int semihosting_getc(void)
 	int ret;
 
 	if (semihosting_infd < 0)  {
-		ch = semihosting_trap(SYSREADC, NULL);
-		ret = ch > -1 ? ch : -1;
+		ret = semihosting_trap(SYSREADC, NULL);
+		ret = ret < 0 ? -1 : ret;
 	} else
 		ret = semihosting_read(semihosting_infd, &ch, 1) > 0 ? ch : -1;
 
-- 
2.34.1