fast_atof: Silence some uninitialized variable warnings

code/fast_atof.h

@@ -360,7 +360,7 @@ inline const char* fast_atoreal_move(const char* c, Real& out, bool check_comma
 // The same but more human.
 inline ai_real fast_atof(const char* c)
 {
-    ai_real ret;
+    ai_real ret(0.0);
     fast_atoreal_move<ai_real>(c, ret);
     return ret;
 }
@@ -368,7 +368,7 @@ inline ai_real fast_atof(const char* c)
 
 inline ai_real fast_atof( const char* c, const char** cout)
 {
-    ai_real ret;
+    ai_real ret(0.0);
     *cout = fast_atoreal_move<ai_real>(c, ret);
 
     return ret;
@@ -376,7 +376,7 @@ inline ai_real fast_atof( const char* c, const char** cout)
 
 inline ai_real fast_atof( const char** inout)
 {
-    ai_real ret;
+    ai_real ret(0.0);
     *inout = fast_atoreal_move<ai_real>(*inout, ret);
 
     return ret;