lib: use american spelling as per style guide

PR-URL: #18226
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Jon Moss <me@jonathanmoss.me>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>

lib/buffer.js

@@ -1204,7 +1204,7 @@ Buffer.prototype.readInt32BE = function readInt32BE(offset, noAssert) {
 //
 // An all-bits-one exponent is either a positive or negative infinity, if
 // the fraction is zero, or NaN when it is non-zero.  The standard allows
-// both quiet and signalling NaNs but since NaN is a canonical value in
+// both quiet and signaling NaNs but since NaN is a canonical value in
 // JavaScript, we cannot (and do not) distinguish between the two.
 //
 // Other exponents are regular numbers and are computed by subtracting the bias