Fix constructing executable path from argv[0].

Do not leave unwanted stuff in the stack in premake_locate_executable(), as the caller only expects exactly one string to be pushed.

src/host/premake.c

@@ -409,6 +409,7 @@ int premake_locate_executable(lua_State* L, const char* argv0)
 			lua_concat(L, 3);
 			path = lua_tostring(L, -1);
 		}
+		lua_pop(L, 1);
 	}
 
 	/* If all else fails, use argv[0] as-is and hope for the best */
@@ -428,6 +429,7 @@ int premake_locate_executable(lua_State* L, const char* argv0)
 		}
 
 		path = lua_tostring(L, -1);
+		lua_pop(L, 1);
 	}
 
 	lua_pushstring(L, path);