Avoid uninit warning in dtoa

This code is extremely convoluted, I have no idea whether or not
this one is legitimate. Suppressing with explicit initialization.

Author: nikic

Zend/zend_strtod.c

@@ -3751,7 +3751,7 @@ zend_dtoa
 	*/
 
 	int bbits, b2, b5, be, dig, i, ieps, ilim = 0, ilim0, ilim1,
-		j, j1, k, k0, k_check, leftright, m2, m5, s2, s5,
+		j, j1 = 0, k, k0, k_check, leftright, m2, m5, s2, s5,
 		spec_case = 0, try_quick;
 	Long L;
 #ifndef Sudden_Underflow