Silence some "may be uninitialized when used" warning

Clang was complaining about some variables possibly being uninitialized
when used. The warnings are bogus, but clang can't figure that out. This
silences the warnings.

Reviewed-by: Richard Levitte <levitte@openssl.org>

test/bioprinttest.c

diff --git a/test/bioprinttest.c b/test/bioprinttest.c
index d376cfb..c69a79c 100644
--- a/test/bioprinttest.c
+++ b/test/bioprinttest.c
@@ -92,7 +92,7 @@
     int i;
 
     for (i = 0; i < 5; i++) {
-        char *fspec;
+        char *fspec = NULL;
         switch (i) {
         case 0:
             fspec = "e";
@@ -143,8 +143,8 @@
     int test = 0;
     int i;
     int fail = 0;
-    int prec;
-    char *width;
+    int prec = -1;
+    char *width = "";
     const double frac = 2.0/3.0;
     char buf[80];