hv: add brackets to make operator expression more readable

v1-v2:
Bypass this case:
When binary arithmetic operators of different precedence (e.g. '+'
and '*') are mixed in an expression, parentheses are added to the
sub-expressions using the operator with a higher precedence.

v1:
The operator precedence rules are complicated and it is easy to make a mistake.
So add brackets to make operator expression more readable.

Tracked-On: #861
Signed-off-by: Li, Fei1 <fei1.li@intel.com>

hypervisor/lib/sprintf.c

@@ -567,7 +567,7 @@ charmem(size_t cmd, const char *s_arg, uint32_t sz, struct snprint_param *param)
 	}
 	/* fill mode */
 	else {
-		n = (sz < param->sz - param->wrtn) ? sz : 0U;
+		n = (sz < (param->sz - param->wrtn)) ? sz : 0U;
 		param->wrtn += sz;
 		(void)memset(p, (uint8_t)*s, n);
 	}