[PATCH 3/3] drmgr/drslot_chrp_hea: Prefer strlen() to check for valid string length

[John Paul Adrian Glaubitz]

This fixes the following warning when building with gcc-12 that is
the result of sysfs_dev_path being a fixed-sized array which means
that (char *)sysfs_dev_path never be NULL:

src/drmgr/drslot_chrp_hea.c: In function 'hotplug_port':
src/drmgr/drslot_chrp_hea.c:124:13: error: the comparison will always evaluate 
as 'true' for the address of 'sysfs_dev_path' will never be NULL 
[-Werror=address]
  124 |         if (! hea->sysfs_dev_path) {
      |             ^
In file included from src/drmgr/drpci.h:25,
                 from src/drmgr/rtas_calls.h:25,
                 from src/drmgr/dr.h:30,
                 from src/drmgr/drslot_chrp_hea.c:31:
src/drmgr/ofdt.h:84:25: note: 'sysfs_dev_path' declared here
   84 |         char            sysfs_dev_path[DR_PATH_MAX];
      |                         ^~~~~~~~~~~~~~

Signed-off-by: John Paul Adrian Glaubitz <glaub...@physik.fu-berlin.de>
---
 src/drmgr/drslot_chrp_hea.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/drmgr/drslot_chrp_hea.c b/src/drmgr/drslot_chrp_hea.c
index 98b96e0..714752a 100644
--- a/src/drmgr/drslot_chrp_hea.c
+++ b/src/drmgr/drslot_chrp_hea.c
@@ -121,7 +121,7 @@ hotplug_port(int action, struct dr_node *hea, struct 
dr_node *port)
 
        say(DEBUG, "Attempting to hotplug %s Port.\n", action_str);
        
-       if (! hea->sysfs_dev_path) {
+       if (!strlen(hea->sysfs_dev_path)) {
                say(DEBUG, "Non-existant sysfs dev path for Port, hotplug "
                    "failed.\n");
                return -EINVAL;
-- 
2.30.2