[mlir][openacc] NFC Fix acc.databounds description incorrect bullet

[razvanlupusoru]

Summary

A dash used in description is an automatic bullet in documentation
if it is the first character of the line. The dash used in the
particular location being fixed was intended to be a separator.
Thus move it to previous line to fix incorrect bullet-ization.

[clementval]

LGTM

mlir/include/mlir/Dialect/OpenACC/OpenACCOps.td

def OpenACC_DataBoundsOp : OpenACC_Op<"bounds",
   let summary = "Represents normalized bounds information for acc data clause.";
 
   let description = [{
     This operation is used to record bounds used in acc data clause in a
     normalized fashion (zero-based). This works well with the `PointerLikeType`
     requirement in data clauses - since a `lowerbound` of 0 means looking
     at data at the zero offset from pointer.
 
-    The operation must have an `upperbound` or `extent` (or both are allowed
-    - but not checked for consistency). When the source language's arrays are
+    The operation must have an `upperbound` or `extent` (or both are allowed -
+    but not checked for consistency). When the source language's arrays are
     not zero-based, the `startIdx` must specify the zero-position index.
 
     Examples below show copying a slice of 10-element array except first element.
     Note that the examples use extent in data clause for C++ and upperbound
     for Fortran (as per 2.7.1). To simplify examples, the constants are used
     directly in the acc.bounds operands - this is not the syntax of operation.
 
     C++: