fix warnings: using the result of an assignment as a condition without parentheses [-Wparentheses]
fix warnings: using the result of an assignment as a condition without parentheses [-Wparentheses]

Don't unnecessarily assign to variables within the *boolean* expression
of a conditional.

Signed-off-by: Giel van Schijndel <b1c1d8736f20db3fb6c1c66bb1455ed43909f0d8@mortis.eu>

wastholm/bitcoin,wastholm/bitcoin,wastholm/bitcoin,wastholm/bitcoin,wastholm/bitcoin,wastholm/bitcoin