Avoid keyword arguments to Record.check_field.

Since commit 21764cf, the optional
parameter to wfdb.io.record.BaseRecord.check_field is called
"required_channels", not "channels".  The semantics appear equivalent.

Several callers were still referring to the old name "channels", while
most callers simply use positional arguments.  Change all callers to
use positional arguments for consistency.

Author: Benjamin Moody

wfdb/io/_signal.py

@@ -295,7 +295,7 @@ def set_p_features(self, do_dac=False, expanded=False):
                 self.e_p_signal = self.dac(expanded)
 
             # Use e_p_signal to set fields
-            self.check_field("e_p_signal", channels="all")
+            self.check_field("e_p_signal", "all")
             self.sig_len = int(
                 len(self.e_p_signal[0]) / self.samps_per_frame[0]
             )
@@ -361,7 +361,7 @@ def set_d_features(self, do_adc=False, single_fmt=True, expanded=False):
         if expanded:
             # adc is performed.
             if do_adc:
-                self.check_field("e_p_signal", channels="all")
+                self.check_field("e_p_signal", "all")
 
                 # If there is no fmt set it, adc_gain, and baseline
                 if self.fmt is None:
@@ -393,7 +393,7 @@ def set_d_features(self, do_adc=False, single_fmt=True, expanded=False):
                 self.d_signal = self.adc(expanded)
 
             # Use e_d_signal to set fields
-            self.check_field("e_d_signal", channels="all")
+            self.check_field("e_d_signal", "all")
             self.sig_len = int(
                 len(self.e_d_signal[0]) / self.samps_per_frame[0]
             )