[css-easing-1] Remove bogus duplicate dfn-for (#7076)

Author: dontcallmedom

css-easing-1/Overview.bs

@@ -172,7 +172,7 @@ A <a>cubic B&eacute;zier easing function</a> has the following syntax
 
 The meaning of each value is as follows:
 
-<dl dfn-type="value" dfn-for="cubic-bezier-easing-function, <cubic-bezier-easing-function>">
+<dl dfn-type="value" dfn-for="<cubic-bezier-easing-function>">
 
 :   <dfn>ease</dfn>
 ::  Equivalent to ''cubic-bezier(0.25, 0.1, 0.25, 1)''.
@@ -259,7 +259,7 @@ It has following syntax:
 
 The meaning of each value is as follows:
 
-<dl dfn-type=value dfn-for="step-easing-function, <step-easing-function>">
+<dl dfn-type=value dfn-for="<step-easing-function>">
 
 :   <dfn>step-start</dfn>
 ::  Computes to ''steps(1, start)''
@@ -283,7 +283,7 @@ The meaning of each value is as follows:
     The second parameter, which is optional, specifies the [=step position=]
     using one of the following values:
 
-    <dl dfn-type=value dfn-for="step-position, <step-position>">
+    <dl dfn-type=value dfn-for="<step-position>">
 
     :   <dfn value for="steps()">jump-start</dfn>
     ::  The first rise occurs at [=input progress value=] of 0.

css-easing-2/Overview.bs

@@ -169,7 +169,7 @@ A <a>cubic B&eacute;zier easing function</a> has the following syntax
 
 The meaning of each value is as follows:
 
-<dl dfn-type="value" dfn-for="cubic-bezier-easing-function, <cubic-bezier-easing-function>">
+<dl dfn-type="value" dfn-for="<cubic-bezier-easing-function>">
 
 :   <dfn>ease</dfn>
 ::  Equivalent to ''cubic-bezier(0.25, 0.1, 0.25, 1)''.
@@ -256,7 +256,7 @@ It has following syntax:
 
 The meaning of each value is as follows:
 
-<dl dfn-type=value dfn-for="step-easing-function, <step-easing-function>">
+<dl dfn-type=value dfn-for="<step-easing-function>">
 
 :   <dfn>step-start</dfn>
 ::  Computes to ''steps(1, start)''
@@ -280,7 +280,7 @@ The meaning of each value is as follows:
     The second parameter, which is optional, specifies the [=step position=]
     using one of the following values:
 
-    <dl dfn-type=value dfn-for="step-position, <step-position>">
+    <dl dfn-type=value dfn-for="<step-position>">
 
     :   <dfn value for="steps()">jump-start</dfn>
     ::  The first rise occurs at [=input progress value=] of 0.