check return value of mkdir()

Also gives a more sensible error message where get_log_path() is used.
fixes CID 27696 found by Coverity

sched/file_upload_handler.cpp

@@ -677,7 +677,9 @@ int main(int argc, char *argv[]) {
 
     installer();
 
-    get_log_path(log_path, "file_upload_handler.log");
+    if (get_log_path(log_path, "file_upload_handler.log") == ERR_MKDIR) {
+        fprintf(stderr, "Can't create log directory '%s'  (errno: %d)\n", log_path, errno);
+    }
 #ifndef _USING_FCGI_
     if (!freopen(log_path, "a", stderr)) {
         fprintf(stderr, "Can't open log file '%s' (errno: %d)\n",

sched/sched_main.cpp

@@ -429,7 +429,9 @@ int main(int argc, char** argv) {
         }
     } else {
         char *stderr_buffer;
-        get_log_path(path, "scheduler.log");
+        if (get_log_path(path, "scheduler.log") == ERR_MKDIR) {
+            fprintf(stderr, "Can't create log directory '%s'  (errno: %d)\n", path, errno);
+        }
 #ifndef _USING_FCGI_
         char buf[256];
         if (!freopen(path, "a", stderr)) {

sched/sched_util_basic.cpp

@@ -143,7 +143,7 @@ int try_fopen(const char* path, FCGI_FILE*& f, const char *mode) {
     return 0;
 }
 
-void get_log_path(char* p, const char* filename) {
+int get_log_path(char* p, const char* filename) {
     char host[256];
     const char *dir;
 
@@ -153,10 +153,13 @@ void get_log_path(char* p, const char* filename) {
     dir = config.project_path("log_%s", host);
     sprintf(p, "%s/%s", dir, filename);
     mode_t old_mask = umask(0);
-    mkdir(dir, 01770);
     // make log_x directory sticky and group-rwx
     // so that whatever apache puts there will be owned by us
+    int retval = mkdir(dir, 01770);
     umask(old_mask);
+    if (retval && errno != EEXIST) return ERR_MKDIR;
+
+    return 0;
 }
 
 static void filename_hash(const char* filename, int fanout, char* dir) {

sched/sched_util_basic.h

@@ -38,7 +38,7 @@ extern void daemon_sleep(int);
 extern bool check_stop_sched();
 extern void install_stop_signal_handler();
 extern int try_fopen(const char* path, FILE*& f, const char* mode);
-extern void get_log_path(char*, const char*);
+extern int get_log_path(char*, const char*);
 
 // convert filename to path in a hierarchical directory system
 //